<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let left = "苹果";
        let right = "橘子";
      
        let table;//空变量
        table = left;
        
        left = right; 
        right = table;
        console.log(left, right);
    </script>
</body>
</html>